I had checked SW a couple of days ago, and it was $95 each way from BWI (same as we are paying for December). I think that's good, considering they usually start out double that (and I'm not necessarily going to WDW in March, but considering it).
Edited: oops I spoke too soon! Now it's $134 or something each way. Definitely not booking that - we can go nonstop to Puerto Rico for less!!!!